text: #include "kernel/types.h"
  #include "kernel/stat.h"
  #include "user/user.h"
  #include "kernel/param.h"
  
  
  
  char *argv[5];
  
  int
  read_line(char *line)
  {
    char buf;
    int count = 0;
    while(read(0, &buf, sizeof(buf)) == sizeof(buf) && buf != '\n') {
      *line++ = buf;
      count++;
    }
    *line = '\0';
    return count;
  }
  
  
  
  
  int
  main(int argc, char *argv[])
  {
    if (argc < 2){
      printf("wrong param\n");
      exit();
      }
      char line[50];
      memset(line,0,sizeof(line));
      while(read_line(line) != 0 ){
        char * arg[MAXARG];
        char** p;
        memset(arg,0,sizeof(arg));
        p = arg;
        for(int i = 1;i< argc;i++){
          *p++ = argv[i];
        }
        *p++ = line;
        // printf("line:%s\n",line);
        int pid;
        // for(int i = 0;i<5;i++){
        //  printf("arg %s\n", arg[i]);
        // }
        // printf("argv[1] %s\n",argv[1]);
        if ((pid = fork() ) == 0){
          //printf("%s,%s\n", );
          exec(argv[1], arg);
        }
        wait();
      }
    exit();
  }
  